DISSERTATION RESEARCH: Sources of Selection on a Complex Signal in Sparrows

动物使用信号来识别自己物种的潜在配偶，并评估潜在配偶的质量。因此，个体选择配偶的过程可能在物种形成中发挥作用。鸟鸣是研究包括人类言语在内的动物信号的产生、感知、发育和功能的重要模式系统。这项拟议的研究旨在确定鸟鸣的产生、感知和功能如何影响鸟鸣随时间变化的方式。最近在五种不同的白冠麻雀(Zonotrichialeucphrys)身上展示了一种有趣的模式，在30年的时间里，歌曲的颤音部分发生了变化。这种模式表明，颤音可能是由于雌性选择的选择或通过与形态或栖息地结构的相关变化而发生变化。这项拟议的研究通过实验和观察来检验雌性选择、形态变化和栖息地变化在解释颤音进化模式方面的相对重要性。这项研究首次在单个物种中评估了这些多重力量是否会影响歌唱随时间的变化，以及在多个种群中选择和限制歌唱之间的潜在平衡。这个项目的智力价值在于增加了对动物信号如何以及为什么随着时间的推移而变化的理解，更广泛地说是增加了对驱动物种形成的过程的科学理解。广泛的影响：这个项目将支持一名女研究生的培训，并增加她作为女性在科学领域实现职业目标的机会。该项目的前期工作已经为几名理科本科生的研究教育做出了额外贡献，其中包括来自代表性不足群体的妇女。该项目还将支持杜克大学和雷耶斯角鸟类天文台(PRBO)之间的合作。这项合作的一部分将包括交流关于白冠麻雀繁殖栖息地和歌唱行为的长期趋势的知识，这可以在了解影响鸣鸟种群生存能力的因素方面发挥宝贵的作用，从而有助于未来对它们的保护。最后，该项目的工作将导致长期保存和提供一套重要的白冠麻雀种群30年来的现场录音，目前保存在加州科学院。

Animals use signals to identify potential mates of their own species, and also to assess the quality of potential mates. Thus, the processes by which individuals choose mates may play a role in speciation. Bird song is an important model system for studying the production, perception, development, and function of animal signals, including human speech. The proposed research aims to identify how the production, perception and function of bird song influence the way bird song changes over time. An interesting pattern of change in the trilled portion of songs over a 30-year period was demonstrated recently in five different populations of white-crowned sparrows (Zonotrichia leucophrys). This pattern suggests that trills may be changing due to selection by female choice or through correlated change with morphology or with habitat structure. The proposed research uses experiments and observations to test the relative importance of female choice, morphological change, and habitat change in explaining patterns of trill evolution. This study is the first to assess in a single species whether these multiple forces influence changes in song over time and the potential balance between selection and constraints on song in multiple populations. The intellectual merit of this project is to increase understanding of how and why animal signals change over time and more generally to increase scientific understanding of processes driving speciation.Broader impacts: This project will support the training of one female graduate student and increase her chances of achieving her professional goals as a woman in science. Preliminary work on this project has already additionally contributed to the research education of several undergraduate women in science, including those from under represented groups. This project also will support collaboration between Duke University and the Point Reyes Bird Observatory (PRBO). Part of this collaboration will include an exchange of knowledge on long-term trends in white-crowned sparrow breeding habitat and song behavior, which can play a valuable role in understanding the factors that affect the viability of songbird populations and thus contribute to their conservation in the future. Finally, work on this project will lead to long-term preservation and availability of an important set of field audio recordings of white-crowned sparrow populations over a 30-year period and currently archived at the California Academy of Science.